Table 2.
The risk of bias of included studies.
| Study | Q1 | Q2 | Q3 | Q4 | Q5 | Q6 | Q7 | Q8 | Q9 |
|---|---|---|---|---|---|---|---|---|---|
| Yassa 2020 | N | U | U | Y | NA | Y | Y | Y | U |
| García-Portilla 2020 | Y | N | Y | Y | U | Y | Y | Y | U |
| Cakiroglu 2020 | N | U | U | U | U | Y | U | Y | U |
| González-Blanco 2020 | Y | N | Y | Y | U | Y | Y | Y | U |
| Yocum 2021 | N | N | U | Y | U | Y | Y | Y | Y |
| Minahan 2020 | Y | N | Y | Y | U | Y | Y | Y | U |
| Pinkham 2021 | Y | N | U | Y | U | Y | U | Y | U |
| Al-Sofiani 2020 | Y | N | Y | Y | U | Y | Y | Y | U |
| Senkalfa 2020 | N | N | U | Y | U | Y | U | Y | U |
| Dadra 2020 | N | N | N | Y | NA | Y | U | Y | NA |
| Justo-Alonso 2020 | Y | N | Y | Y | U | Y | Y | Y | U |
| Balci 2021 | U | U | N | Y | NA | Y | Y | Y | NA |
| Muro 2020 | U | U | Y | Y | U | Y | U | N | Y |
| Xia 2020 | N | N | U | Y | U | Y | Y | Y | U |
| Karantonis 2021 | U | U | N | Y | U | Y | Y | Y | U |
| López-Morales 2020 | Y | N | U | Y | U | Y | Y | Y | U |
| Sayeed 2021 | Y | N | Y | Y | NA | Y | Y | Y | U |
| Stocker 2021 | Y | N | Y | Y | U | Y | Y | Y | U |
| Poll-Franse 2021 | Y | U | Y | Y | NA | Y | Y | Y | N |
| Dobler 2020 | N | N | U | Y | NA | Y | Y | Y | N |
| Zach 2021 | Y | N | Y | Y | U | Y | Y | Y | U |
| Burrai 2020 | N | U | U | Y | U | Y | Y | Y | U |
| Ciprandi 2020 | Y | N | Y | Y | U | Y | N | Y | U |
| Mirzaei 2021 | U | N | Y | Y | U | Y | Y | Y | U |
| Zhou 2020 | Y | N | Y | Y | U | Y | Y | Y | U |
Note. Q1, Was the sample frame appropriate to address the target population?; Q2, Were study participants sampled in an appropriate way?; Q3, Was the sample size adequate?; Q4, Were the study subjects and the setting described in detail?; Q5, Was the data analysis conducted with sufficient coverage of the identified sample?; Q6, Were valid methods used for the identification of the condition?; Q7, Was the condition measured in a standard, reliable way for all participants?; Q8, Was there appropriate statistical analysis?; Q9, Was the response rate adequate, and if not, was the low response rate managed appropriately? Abbreviations. N, No; NA, not applicable; U, unclear; Y, yes.